One of the more distressing features of these supposedly godless times is the encouragement of a kind of slack-jawed piety; we must be nice about all religious institutions simply because they are, um, religious. Nowhere was this better illustrated than within the acres of newsprint devoted to John Paul II on his death. According to most of the humbug being dished out for our perusal, we have spent the past quarter of a century in the presence of a living saint, personally responsible for the liberation of millions from the iron yoke of communism, herald of ecumenism, symbol of hope for the oppressed, beacon of the faith.

John Cornwell's book, unimaginably timely, may cause some people to re-evaluate this position. There is no doubt that the Pope was a prime mover in the collapse of Soviet communism, although he wasn't exactly acting alone. But he is at least partly responsible, if I may be facetious, for the fact that Chelsea are top of the table. No Russian oil billionaires under communism. (Not, as Cornwell acknowledges, that John Paul II approved of billionaires or the excesses of capitalism. But capitalism laughs at finger-wagging from Rome even more than did Josef "how many divisions has the Pope?" Stalin.) Karol Wojtyla's personal experience of totalitarianism gave him a certain degree of authority when it came to facing it down. But Cornwell has a telling phrase: he says that when Wojtyla left Poland "he took a little bit of the Iron Curtain with him".

In other words, he became the most authoritarian of popes, opposed to dissent, however informed. It is interesting to hear that his best known play, The Jeweller's Shop, consists largely of a series of lengthy, untheatrical monologues. He didn't do dialogue. The post of diaboli advocatus, appointed specifically in order to discredit candidates for sainthood, was abolished; another way of not hearing another point of view.

As for ecumenism, the idea that John Paul II was a force for understanding between churches would make a cat laugh. As far as he was concerned, and his concern rather set the seal on things, there was only one true church, and that was his. Officially, says Cornwell, "the Archbishop of Canterbury, by this reckoning, was a lay man of dubious religious affiliations and by no means head of an authentic church".

Incidentally, you will find quite a bit in here about Cardinal Ratzinger, the new Pope Benedict XVI. "New" is an unusual word to describe a 78-year-old, and you will also find ample confirmation that "breath of fresh air" is, I'm prepared to wager, pretty much the last phrase anyone is going to use about any of his pronouncements or initiatives, assuming there are any. One pronouncement he did sign was Dominus Jesus, "endorsed, purposefully and very clearly, by John Paul". This was an attack on relativism, indeed on religious tolerance: it simply (that is, not so simply) said that every other religion was wrong.

While this may have upset many grownup Catholics, it does put an end to those childish "which is the right religion?" type questions, and we may think fondly of the phrase Father Jack is taught to parrot in an episode of Father Ted: "that would be an ecumenical matter". On other matters, though, we can be less indulgent, such as John Paul II's dismaying attitude to sex and the assertion that condoms were not only unholy, they were holey and let the Aids virus in through the gaps. One wonders how many have died because he said that. He certainly believed in responsibility for one's actions being manifested by the divine will; when he slipped in the shower and broke his femur in 1994, "he told the faithful that God was asking him to suffer in reparation for the sins against unborn children". So if you have ever used a contraceptive device or had an abortion, it's thanks to you the Pope had to have a new hip. And in his response to the child abuse scandal among the priesthood he hardly covered himself with glory.

Of course, sometimes Cornwell puts quite a ferocious spin on some of the facts. He is out to make a stir. But even the Tablet said this was a book worth reading. Don't take my word for it.